基于LabVIEW的小口径管道内径测试系统

设计了一种小口径管道内径测试系统,该系统利用电容传感器通过接触式测量得到内径值,同时激光测距仪通过反射相位差得到电容传感器在管道内的轴向位置信息.传感器通过串口与计算机连接,应用LabVIEW软件进行最小二乘拟合得到最优曲线,并实时显示管道内各个位置内径变化量.该系统克服了小口径管道的测量困难,并且较传统的测量方法具有测量精度高、重复性好及操作简便的优点.     

基于ACP3000高精度温湿度测量的设计与实现

应用罗卓尼克的ACP3000连接热电阻RTD和湿敏电容传感器实现热工计量过程中的高精度温湿度测量。分析温湿度传感器的测量原理,研究ACP3000的数据记录和传感器标定功能。验证了ACP3000用于现场高精度温湿度测量的可行性。     

电容层析成像系统中电容传感器参数优化设计

电容层析成像系统中,图像重建的质量主要依赖于电容敏感场分布的均匀性,这一性质又由传感器的几何和材料参数决定,因此传感器的设计尤为重要．根据敏感场颁上的均匀性,灵敏程度和电容测量技术,确定了传感器的优化参数;在多因素轮换的基础上,采用正交设计法进行电容传感器参数的计算机辅助设计,从而快速地获得一组最优参数．在实际应用中,概据此优化参数制造的电容传感器获得了较为理想的重建图像．     

容栅电子长度测量系统

一、概述线纹电子长度测量系统中通常包括光栅,同步感应器,磁栅和容栅四种测量系统。容栅电子长度测量系统是七十年代末,八十年代初国际上开始发展起来的一种新颖位移传感器,国内在八十年代陆续引进了容栅器件进行组装。容栅测量系统有几种不同的类型,但其基本原理都应用了电容差动感应的原理。本文介绍的是一种高分辨率的容栅电子长度测量系统。二、工作原理图1　　容栅电子长度测量系统的基本原理如图1所示,它包括一个差动电容传感器,在电容传感器的一边至少有一块接收极板,在电容传感器的另一边至少有两块发射极板。电容传感器两边能作相…     

调焦光路中超精密双等位环平板电容位移传感器研究

在应用共焦显微镜原理实现对超精加工表面的几何量测量中,设计了一种环状的电容位移传感器,对物镜的调焦位移进行测量,使测量光轴从极板的中心孔穿过,测量位移方向与光路的光轴重合,与阿贝原理相符;采用微机电系统(MEMS)工艺加工双等位环电容极板,电容器极板很薄,间隙小于2μm,减小边缘效应附加电容,从而极大地提高了测量的线性和测量精度.设计了处理电路,对该传感器进行了标定,在0～30μm内,其线性度为0.05%,分辨力优于0.01μm.     

基于PC104的转速传感器标定系统硬件设计

为提高产品出厂合格率和可信度,转速传感器出厂前需要进行标定.文章在介绍了转速传感器测量原理的基础上,针对转速传感器的标定设计了基于PC104的转速传感器的标定系统硬件平台,重点介绍了该系统的电路硬件设计及其结构平台的设计.     

基于多极板电容传感器测量原油含水率的研究

设计了测量原油含水率的多极板式电容传感器及测量电路;建立了多极板式电容传感器测量原油含水率的数学模型,得到了原油含水率变化量与多极板式电容传感器等效电容变化量之间的函数关系.进行了五极板式电容传感器和单极板式电容传感器测量油水混合物含水率的对比实验.实验结果表明采用五极板式电容传感器测量油水混合物的含水率,相对于采用单极板式电容传感器测量油水混合物的含水率的测量精度有大幅度的提高;而且采用五极板式电容传感器测量油水混合物的含水率,无论是在低含水率端还是在高含水率端其测量结果都比较稳定.     

新型旋转角加速度传感器特性标定系统的研究

针对旋转角加速度传感器的标定问题,构建了一套特性标定系统。首先分析了永磁旋转角加速度传感器的工作原理,并提出了一种基于调频调压电源供电的、异步电动机纯单相运行的、可调频调幅的旋转角加速度脉动源系统;然后采用传统增量式光栅编码器和现场可编程门阵列构建了旋转角加速度测量系统;最后通过比较旋转角加速度传感器的输出电压峰值和测量系统得到的实际旋转角加速度峰值,对传感器输出特性进行了标定,得到传感器输出电压与角加速的特性曲线,线性误差为1.81%。     

谐振梁在高量程加速度传感器非线性测试中的应用

介绍了一种高量程加速度传感器非线性的新测量方法。用谐振梁与振动台系统组成新的谐振系统．这一系统对振动台的振动信号具有放大作用,从而解决了用小量程振动台标定大量程加速度传感器非线性的难题。详述了用谐振梁法测量高量程加速度传感器非线性的实际操作过程,总结了试验过程中的方法和经验,对高量程加速度传感器非线性测量具有实际指导作用。     

谐振筒式液体密度传感器的设计

短筒谐振式密度传感器是以短筒谐振管为核心,基于正反馈原理,由激振元件、拾振元件、谐振子和放大电路组成的高品质闭环谐振系统．采用有限元法分析方法,研究计算了圆筒谐振子的静力学特性和模态响应等动力学特性;设计了短筒谐振管传感器和闭环振荡电路及单片机信号处理系统;分析了温度、压力、黏度等因素对测量结果的影响,对传感器进行了标定,并采用温度补偿方法提高了传感器的测量精度．实验表明20℃时传感器测量结果的不确定度为0.96kg／m3．圆筒谐振燃油密度传感器测量精度达到0.4kg,m3．     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from